Watch the first trailer for 'Salinger,' the movie

J.D. Salinger's "Catcher in the Rye" was one of the most popular books of the 1950s. Adolescent narrator Holden Caufield's reluctance to go along with societal norms helped lay the psychic groundwork of the countercultural movement of the 1960s.

But where the Beats rode that wave, with Allen Ginsberg reading poetry at massive student demonstrations, Salinger withdrew. He'd been a New Yorker, but he moved to rural New England, away from the center of publishing. His last published work appeared in 1965. He refused interviews after 1980.

He became, some would say, the Howard Hughes of 20th century fiction. Clearly brilliant, with huge successes behind him, he stopped communicating with the outside world. Lawyers fiercely guarded his privacy.

Salinger published four books and some assorted short stories before he died in 2010, at age 91. But fans always wondered: Was he writing all along?

In the trailer above for "Salinger," a sweeping biographical documentary coming out in September, someone says she saw manuscripts. That's Joyce Maynard, who was a precocious 18-year-old when she wrote to Salinger in 1972. She moved to Cornish, New Hampshire, where she lived with Salinger for several months.

Maynard, now an author in her own right, is one of the literary figures in the film; Tom Wolfe and A. Scott Berg also appear in the trailer. They're joined by a host of Hollywood figures -- John Cusack, Danny DeVito, Edward Norton, Martin Sheen -- talking about Salinger's wide influence.

The film is directed by Shane Salerno. The "Armageddon" screenwriter spent $2 million of his own money to produce the feature documentary, which is being accompanied by a 704-page biography being published by Simon & Schuster.